Among the many problems endured by patients suffering from symptomatic HIV infection, which includes inter alia AIDS (Acquired Immune Deficiency Syndrome) and ARC (AIDS Related Complex), are loss of appetite with consequent loss of weight. This loss of appetite and loss of weight further debilitates the patients and increases the many problems associated with the HIV infection.
The compound delta-9-tetrahydrocannabinol, which is the active ingredient in marijuana and which was produced chemically as described in U.S. Pat. No. 3,668,224, has been used as an antiemetic to relieve nausea and vomiting in patients receiving cancer chemotherapy.
A number of cancer investigators have used delta-9-tetrahydrocannabinol to attempt to increase appetite and modify weight loss in cancer patients. For example, in a randomized double-blind crossover study employing oral delta-9-tetrahydrocannabinol and prochlorperazine, 50% of the subjects on delta-9-tetrahydrocannabinol reported an increased food intake while only 29% had a similar response on the prochlorperazine.1 In another study of similar design and using the same medications, patients on delta-9-tetrahydrocannabinol reported feeling more hungry than patients on prochlorperazine.2 Results suggestive of an appetite stimulating effect were also noted by Ekert, et al.3 in groups of children and adolescents 6-19 years of age administered delta-9-tetrahydrocannabinol, prochlorperazine or metaclopramide in crossover design studies.
1Sallan, S E; Cronin, C; Zelen, M; and Zinberg, N E (Sidney Farber Cancer Institute, Boston, Mass.): Antiemetics in patients receiving chemotherapy for cancer. A randomized comparison of delta-9-tetrahydrocannabinol and prochlorperazine. N. Engl. J. Med. 301:135-138 (Jan. 17) 1980, No. 3. 
2 Ungerleider, J T; Andrysiak, T; Fairbanks, L; Gooodnight, J; Sarna, G; and Jamison, K. (UCLA Center for the Health Sciences, Los Angeles, Calif.): Cannabis and cancer chemotherapy. A comparison of oral delta-9-THC and prochlorperazine. Cancer 50:636-645 (Aug. 15) 1982, No. 4. 
3 Ekert, H; Waters, K D; Jurk, I H; Mobilia, J; and Loughnan, P. (Royal Children""s Hospital, Melbourne, Australia): Amerlioration of cancer chemotherapy-induced nausea and vomiting by delta-9-tetrahydrocannabinol. Med. J. Aust. 2:657-659 (Dec. 15) 1979. 
In a double blind study, Regelson, et al.4 observed that advanced cancer patients on chemotherapy receiving delta-9-tetrahydrocannabinol maintained their weight better than those not receiving the delta-9-tetrahydrocannabinol.
4 Regelson W, Butter J R; Schultz J; Kirk T; Peek L; Green M L; Delta-9-tetrahydrocannabinol, (delta-9-THC) as an effective antidepressant and appetite-stimulating agent in advanced cancer patients. The pharmacology of marihuana, (Braude M C and Szara S eds) Raven Press, N.Y. (1976; pp. 763-766. 
In an open study, Wadleigh, et al.5 observed appetite increases and a lessening of the rate of weight loss in cancer patients.
5 Wadleigh, R; Spaulding, M; Lembersky, B; Zimmer, M; Shepard, K; Plasse, T: Dronabinol enhancement of appetite in cancer patients. Proceedings, 1990 American Society of Clinical Mycology Meeting. 
It is accordingly a primary object of the present invention to provide for the treatment of patients suffering from symptomatic HIV infection so as to improve the appetite and induce weight gain in such patients.
Other objects and advantages of the present invention will be apparent from a further reading of the specification and of the appended claims.
With the above and other objects in view, the present invention mainly comprises the administration to a patient suffering from symptomatic HIV infection of an appetite stimulating effective amount of delta-9-tetrahydrocannabinol.
The delta-9-tetrahydrocannabinol is preferably administered orally as dronabinol (delta-9-tetrahydrocannabinol in sesame oil-containing capsules). Administration is also possible to achieve the effects of the present invention when the delta-9-tetrahydrocannabinol is in the form of tablets, suppositories, intranasal administration, transdermal administration, inhalants and sublingual administration, as well as administration by injection.
Side effects, such as nausea and CNS effects, may vary with the dosage of the delta-9-tetrahydrocannabinol. It is a further object of this invention to optimize the dosage regimen so as to minimize such side effects.
The following is given to further illustrate the present invention. The scope of the invention is not, however, meant to be limited to the specific details thereof.